Turbulence-induced optical loss and cross-talk in spatial mode multiplexed or single-mode free-space communication channels

• Main Authors: Kravtsov, K. S, Zhutov, A. K, Radchenko, I. V, Kulik, S. P
• Format: Journal Article
• Language: English
• Published: 16-11-2018
• Subjects: Physics - Quantum Physics
• DOI: 10.48550/arxiv.1811.07034

Single-mode or mode multiplexed free-space atmospheric optical channels draw
increasingly more attention in the last decade. The scope of their possible
applications spans from the compatibility with the telecom WDM technology,
fiber amplifiers, and modal multiplexing for increasing the channel throughput
to various quantum communication related primitives such as entanglement
distribution, high-dimensional spatially encoded quantum key distribution, and
relativistic quantum cryptography. Many research papers discuss application of
specific mode sets, such as optical angular momentum modes, for communication
in the presence of atmospheric turbulence. At the same time some basic
properties and key relations for such channels exposed to the atmospheric
turbulence have not been derived yet. In the current paper we present simple
analytic expressions and a general framework for assessing probability density
functions of channel transmittance as well as modal cross-talk coefficients.
Under some basic assumptions the presented results can be directly used for
estimation of the Fried parameter of the turbulent channel based on the
measured statistics of the fundamental mode transmittance coefficient.